The color of the iris is determined by the amount of pigment present in this eye structure and the system is the same as the one that determines your skin color and your hair color. It is controlled by your genes, not your diet. No pigment at all (in the case of an albino) results in a pink iris. Some pigment causes the iris to appear blue. Increasing amounts of iris pigment produce green, hazel, and brown eyes. There actually are two pigments, melanin and lipochrome, which determine eye color. Melanin (brown, red, black) comes in several varieties and is also the pigment that controls skin and hair color. Lipochrome is yellowish-brown. There is nothing you can eat that would affect the amount of these pigments that your body produces.